Yeah, Neal could play WLB while Gregory (or Ojulari) played the LEO spot.
The LEO position is just basically a Weakside DE who is in a two (or three) point stance in a wide-9 alignment. You still have a “front four” (one of them being the LEO) with 3 LB’s and 4 DB’s in base, although most of the time they’d probably be in a nickel which would be with the LEO standing in a wide-9 alignment with two LB’s (say LVE and Neal) and 5 DB’s.
Here is a shot of the Seattle defense that Quinn ran. You can see that the LEO is out on the edge (here in a 3 point stance). You can also see there are 3 other DL as well as 3 LB’s. The SLB is lined up on the line of scrimmage while the MLB and the WLB are lined up in a more traditional off the ball position.
So yes, Neal would definitely play at the same time as a LEO.
If Jaylon is playing the SAM, he could play up at the LOS and have some more opportunities to get after the QB than he has had in previous seasons, with LVE in the middle and Neal as the Will. Personally, I think that Jaylon is pretty decent getting pressure on the QB.